A sheet for whitening cosmetics comprises a sheet-like substrate and an adhesive layer which comprises a wet pressure-sensitive adhesive composition formed on the substrate. The whitening component includes vitamin C or its derivatives such as magnesium L-ascorbyl-2-phosphate, vitamin E nicotinate, kojic acid, hydroquinone, ellagic acid, albumin, galenical extracts, and rice bran extracts. Kojic acid and magnesium L-ascorbyl-2-phosphate are preferred. By contacting the adhesive layer with water and/or a hydrophilic medium such as alcohols, e.g., methanol, ethanol, etc., the wet pressure-sensitive adhesive composition exhibits excellent stickiness and excellent applicability to skin as well as excellent whitening effect with alleviating or eliminating stains, freckles, non-transparency, etc. on the skin.